Okay, so allow me to share with you the things I've already done.

1. Engine wouldn't turn over, thought I was out of gas. Filled up, no dice.
2. Assumed fuel pump which actually was dead. Changed it.
3. Still won't start. Thought perhaps the filter was clogged. Changed filter, still won't start.
4. Checked relays with multimeter, no faults.
5. Checked fuel reset, wasn't tripped.
6. Sat there and pondered total destruction of truck, decided to post on the forums...

I have a 99 Ford F150 XLT Triton V8 4.6L and I'm at wits end and grasping at straws.

Any clues?

Edit:
New Spark plugs installed today. Fuel Injectors cleaned, new O2 Sensor. Still wont start. Truly at wits end now.

 

Does Ur try and turnover or do you turn the key and nothing happens? Do any of your gauges come on or any lights flash on the gauges??

 

Engine won't turn over or will turn over but won't start?
Won't turn over look at battery, starting system, and grounds.
Will turn over but will not start look at fuel, air filter (could be flooding), and ignition.

 

Battery.

 

The starter works fine, grounds are good. The engine wants to start (judging by the noise) but cannot. Could it be the ***shudder*** sending unit?

 

All electrical is fully functioning. Lights go on, normal start up procedure. Engine cranks, but cannot start. New Spark plugs installed today. Fuel Injectors cleaned, new O2 Sensor. Truly at wits end now.

 

Well the first thing I would do is try another key. If your chip goes bad you can sit there and crank all you want the system won't let the system turn over. next I don't remember if you tried this or not but check that the fuel pump comes on and check your
Fuel pressure

 

look for pending codes or current codes. if i were to guess a sensor it would be a ckp sensor

 

Wow, I feel like a total idiot. I had grabbed my copy which was apparently never verified to have a chip. I drove over to the shop, put the original key in and BAM...Engine started. Oddly, the A/C now works...
Thanks so much for the input and suggestions.

 

Your welcome that's what we're here for lol